Swedish coastal waters see rise in dangerous Vibrio bacteria

Vibrio bacteria have become increasingly common in Sweden's salt and brackish coastal waters, especially in the Öresund region and along the southern Baltic Sea coast. Researchers say the country lacks a comprehensive map of where the bacteria are present and which people are at risk.

The bacteria can cause severe infections such as wound fever, sepsis, and even death, particularly in older individuals or those with weakened immune systems. Warm water above 20 °C combined with algal blooms raises bacterial concentrations, heightening the danger for swimmers.

Microbiologist Betty Collin, a lecturer at Kristianstad University and nurse at Skåne University Hospital, warns that many Swedish doctors are unfamiliar with Vibrio species and their antibiotic resistance, underscoring the need for better awareness and study. The species identified in Swedish waters include Vibrio vulnificus, Vibrio parahaemolyticus and Vibrio cholerae. So far they have not been found in inland lakes or fresh water.